improvement of hwang lo lin scheme based on an id based cryptosystem
Download
Skip this Video
Download Presentation
Improvement of Hwang-Lo-Lin scheme based on an ID-based cryptosystem

Loading in 2 Seconds...

play fullscreen
1 / 12

Improvement of Hwang-Lo-Lin scheme based on an ID-based cryptosystem - PowerPoint PPT Presentation


  • 130 Views
  • Uploaded on

Improvement of Hwang-Lo-Lin scheme based on an ID-based cryptosystem. No author given (Korea information security Agency) Presented by J.Liu. Outline. Introduction Review of the Hwang-Lo-Lin scheme Cryptanalysis The modified ID-based identification scheme Security analysis

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Improvement of Hwang-Lo-Lin scheme based on an ID-based cryptosystem' - brent-leonard


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
improvement of hwang lo lin scheme based on an id based cryptosystem

Improvement of Hwang-Lo-Lin scheme based on an ID-based cryptosystem

No author given

(Korea information security Agency)

Presented by J.Liu

outline
Outline
  • Introduction
  • Review of the Hwang-Lo-Lin scheme
  • Cryptanalysis
  • The modified ID-based identification scheme
  • Security analysis
  • Performance analysis
  • Conclusions
introduction
Introduction
  • ID-based public key cryptosystem.
  • Maurer-Yacobi(1996)Tseng-Jan(1998)

Hwang-Lo-Lin(2004)Horng-Liu-Liu(2005)  This Letter(2005)

  • Hwang et al. developed the improved scheme was suitable for the wireless environment.
review of the hwang lo lin scheme
Review of the Hwang-Lo-Lin scheme
  • TA setup the system parameters as following:
    • N = p1p2 p3p4, where pi are primes and their decimal digits are between 60-70, (pi-1)/2 are odd and pair wise relatively prime.
    • DLP is feasible but factoring N is infeasible.
    • g is a primitive root in each GF(pi).
    • h(.) is an one way hash function.
    • ed = 1 mod (N) and tv = 1 mod (N).
slide5
Cont
  • IDb, IDm: identity of base station(BS) and mobile device(M), respectively.
  • sb = et  logg(IDb2) mod (N) is secret key for BS.
  • sm = et  logg(IDm2) mod (N) is secret key for M.
  • T: timestamp

{N, g, e, h(.)}are public parameters and keep {p1, p2 , p3, p4 , t, v, d } secret.

login and authentication
Login and authentication
  • Choose kR ZN*, computes Y = (IDm2)k mod N , Z = (IDb2)ksmT mod N
  • Sends {IDm, Y, Z, T } to BS.
  • BS computes Z’ = (Y)sbT, checks Z = Z’

If yes then… else….

?

cryptanalysis
Cryptanalysis
  • Attacker forge {IDm, Y1, Z1, T’ } from a valid login message {IDm, Y, Z, T } by Y1 = YrT mod N and Z1 = ZrT’ mod N.
the modified id based identification scheme
The modified ID-based identification scheme
  • The parameters are the same of Hwang’s scheme, but the 4 primes have bit size more than 1024 bits. (DLP OK? about 300 decimal digits)
  • M sends {IDm, Z, T} to BS, where Z = H((IDb2)smT mod N)
  • BS verifies by Z = H((IDm2)sbT mod N)
security analysis
Security analysis
  • Passive replay attack: Changes timestamp T.H((IDm2)sbT mod N) H((IDm2)sbT’ mod N)
  • Active replay attack: The attacker can not change Z and T without sm and sb.
  • ID-stolen attack: The same with 2.
performance analysis
Performance analysis
  • Without random number generator(hash function).
  • Shorter message length (1/2).
  • Fewer exponential operation (21).
  • More suitable in wireless environment.
conclusion
Conclusion
  • Secure
  • More suitable.
ad